According to the further agreement on Multimedia Broadcast Multicast Service (MBMS) Point-to-Multipoint Control Channel (MCCH) in RAN#65bis in March 2009, MCCH is only mapped on Multicast Channel (MCH) in Rel9 eMBMS. It implies that there is a requirement to carry out Multicast Broadcast Single Frequency Network (MBSFN) transmission of MBMS Radio Resource Control (RRC) control signaling on MCH. It requires that different eNBs should have a consistent processing result for RRC signaling for MBMS to guarantee correct MBSFN transmission. This consistent processing result of RRC signaling includes content synchronization of MCCH RRC message Transport Blocks (TBs), exact transmission timing for MCCH messages, and uniform processing for RRC controlling signaling content for all eNBs when state of a service session changes. In order to achieve the multivendor interoperability, some mechanism and rules should be defined and standardized.
A basic transmission solution for MCCH RRC message is as shown in FIG. 6. It is assumed that the MCCH messages will be transmitted according to definitions of Modification Period (MP)/Repetition Period (RP) and all MCCH messages will be outputted within one TB. Transmission of an MCCH message only occurs in each MP and RP. The updating of MCCH messages only occurs at the starting point of each MP, and at a certain time point of each RP only the same MCCH message as in current MP is resent.
It is clear that the timing for transmission of MCCH RRC message TBs is defined and it is identical in different eNBs according to the same NIP and RP configuration. That means synchronization of the transmission timing for MCCH RRC message TBs is guaranteed.
The biggest issue to be resolved by the present invention is to design a mechanism to keep the content synchronization of all the MCCH RRC message TBs. At present, there is no such a solution in the prior art.